Initial revision

From-SVN: r26263

libjava/java/io/InputStreamReader.java

@@ -0,0 +1,151 @@
+/* Copyright (C) 1998, 1999  Cygnus Solutions
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+ 
+package java.io;
+import gnu.gcj.convert.*;
+
+/**
+ * @author Per Bothner <bothner@cygnus.com>
+ * @date April 22, 1998.  
+ */
+/* Written using "Java Class Libraries", 2nd edition, plus online
+ * API docs for JDK 1.2 beta from http://www.javasoft.com.
+ * Status:  Believed complete and correct, but only supports 8859_1.
+ */
+
+public class InputStreamReader extends Reader
+{
+  BufferedInputStream in;
+
+  // Buffer of chars read from in and converted but not consumed.
+  char[] work;
+  // Next available character (in work buffer) to read.
+  int wpos;
+  // Last available character (in work buffer) to read.
+  int wcount;
+
+  BytesToUnicode converter;
+
+  public InputStreamReader(InputStream in)
+  {
+    this(in, BytesToUnicode.getDefaultDecoder());
+  }
+
+  public InputStreamReader(InputStream in, String enc)
+    throws UnsupportedEncodingException
+  {
+    this(in, BytesToUnicode.getDecoder(enc));
+  }
+
+  private InputStreamReader(InputStream in, BytesToUnicode decoder)
+  {
+    super(in);
+    this.in = in instanceof BufferedInputStream  ? (BufferedInputStream) in
+      : new BufferedInputStream(in, 250);
+    converter = decoder;
+    converter.setInput(this.in.buf, 0, 0);
+  }
+
+  public void close() throws IOException
+  {
+    synchronized (lock)
+      {
+	if (in != null)
+	  in.close();
+	in = null;
+	work = null;
+	wpos = wcount = 0;
+      }
+  }
+
+  public String getEncoding() { return converter.getName(); }
+
+  public boolean ready() throws IOException
+  {
+    synchronized (lock)
+      {
+	if (wpos < wcount)
+	  return true;
+	if (work == null)
+	  {
+	    work = new char[100];
+	    wpos = 0;
+	    wcount = 0;
+	  }
+	for (;;)
+	  {
+	    if (in.available() <= 0)
+	      return false;
+	    in.mark(1);
+	    int b = in.read();
+	    if (b < 0)
+	      return true;
+	    in.reset();
+	    converter.setInput(in.buf, in.pos, in.count);
+	    wpos = 0;
+	    wcount = converter.read(work, 0, work.length);
+	    in.skip(converter.inpos - in.pos);
+	    if (wcount > 0)
+	      return true;
+	  }
+      }
+  }
+
+  public int read(char buf[], int offset, int length) throws IOException
+  {
+    synchronized (lock)
+      {
+	int wavail = wcount - wpos;
+	if (wavail > 0)
+	  {
+	    if (length > wavail)
+	      length = wavail;
+	    System.arraycopy(work, wpos, buf, offset, length);
+	    wpos += length;
+	    return length;
+	  }
+	else
+	  {
+	    for (;;)
+	      {
+		in.mark(1);
+		int b = in.read();
+		if (b < 0)
+		  return -1;
+		in.reset();
+		converter.setInput(in.buf, in.pos, in.count);
+		int count = converter.read (buf, offset, length);
+		in.skip(converter.inpos - in.pos);
+		if (count > 0)
+		  return count;
+	      }
+	  }
+      }
+  }
+
+  public int read() throws IOException
+  {
+    synchronized (lock)
+      {
+	int wavail = wcount - wpos;
+	if (wavail > 0)
+	  return work[wpos++];
+	if (work == null)
+	  {
+	    work = new char[100];
+	    wpos = 0;
+	    wcount = 0;
+	  }
+	int count = read(work, wpos, work.length-wpos);
+	if (count <= 0)
+	  return -1;
+	wcount = wpos + count;
+	return work[wpos++];
+      }
+  }
+}